SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4624627a2cdb2eef38d61be347b704f9ae231c94196790bd05a312862c6d862f' 
  AND token = 'xBiJA7JJRo1T9JfueRPGxHiVfCJ6A6fiRw0eG0AxT/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}